Natural-abundance carbon-13 nuclear magnetic resonance spectroscopy will be applied to the study of proteins and glycoproteins in solution. (1) The conformation in solution of the "blue" copper electron transfer protein plastocyanin will be investigated by observing the broadening effect of the copper (in the Cu2 plus state) on 13C resonances. (2) The structural role of aromatic amino acid residues of proteins will be studied by determining conformational differences between intact and chemically modified proteins. (3) Techniques will be developed (and applied) for using natural-abundance 13C NMR for studies of the following properties of glycoprotiens: (a) The primary structure (glycosidic linkages) of the carbohydrate residues: (b) The effect of partial and/or total removal of the carbohydrates. Bovine pancreatic ribonucleaseB, human erythrocyte glycophorin A, and antifreeze glycoproteins from Antarctic fishes will be investigated initially.